Firearm



G. HAMMOND.

FIREARM.

APPLICATION FILED AuG.H, 1918.

fJZx/E'JZLU/f; Gran Hammoni G. HAMMOND.

FIREARM.

APPLICATION FILED AUG81 19|8.

Patented Oct. 17, 1922.

2 SHEETS-SHEET 2.

LZ1/Zult' ujf. Grani Iffclmmnrnull Patented Get. 17, 1922.

UNUEfI-SP p GRANT nAMMoNii; or Nnw VENCONNEQTYICUT,.AssiGNoRor.ONE-THIRD '11o ALVA o. wAs'HBURNE, forrItLTsF1nm3,;.NuisSAGIIUSETIJS,y AND ONE-THIRD 'ro y FREDEMCK e. CRANE, or DALToNfivrAssAonUsETTs. i y

Appiieaa md Angustia, 191s. `seriali-Nq;248,975.'--

To all 'whimivitmay concern. f f Be' itknown that I, GRANT HAMMOND, a

citizen' of' the United States, residing` in New; l Havem in 'the' county of Vl;\lewi'lrl avenfand State of Connecticut, haveinvent'ed a new; and Improved Firearmglof which the follow-A yinvention relates to automatic-f1` fire-f arms,and an object of said inventlomamongf others, 1s to produce a gun offsmp'le construction that has a solid, locked breechat the instant 'of firing, fthus enabling the lmaximum force of the-explosive charge to^be l' utilized; agun with a minimum amount of kickf'7 thus enabling its continued use with-y out producing fa'tigueg'a gun"in"'whichjthe barrel, sights, receiver' 'andhandle are' zall maintained rigidly secured together, 'therevby] giving the weapon vas great 'accuracy as an ordinary pistola 1I have also-shown an improved mounting for the kvk"bolt return spring-overthatjshown in my formerflapplicationof Serial Number 204,921 iled December 1st,1917,which gives freerexit for the exploded shell without sacrificing the generalmethod of removing the-*boltso as to enable the barrel to be cleaned Jrfrom the breech end without dismounting the gun- One form of rearm embodying my invention-'and in the construction and use-ofwhich theobjectsher'ein set Iout,"a's well as others, may be attained, is illustrate'd-V 'in'r the accompanying drawings,"in which-'f' f Figure 1 is a viewl inl elevation of the left side lof the gun with ay portion brokenaway, showing a vertical Asection through the breech-bolt. 'f 1 Figure 2 is a View inside elevation of a portion ofthe part that is broken away'in Figure 1.

"Figure 3 is a rear elevation of the bolt and af portion of the receiver. i

y Figure 4 isa view in elevationof the right side of the gun. Figure 5 is'a plan View Aof the'handle.

'Figure 6 is" a sectional view on the 4lines 6-6of Figuresand 5.v Y

The barrel 1y is screwed into the receiver 2'inthe ordinary,` manner. The receiver is secured tothe handle 8- by'a T-slot connection 3( This method'of attachmentl is simi;

lar tothe construction 'used where the barrel and receiver Vhave a slight vrecoil movement oiifthe handle, lbutin the present construe'- tionthe receiver/is rigidly secured to the-E55 handleI by1a` spring pressed pinneL having a lug isili" engaging a corresponding; recess in'y the receiver.. By pressingin thispinl there-- ceiver may be slid forward anddisengaged fromthe handle.` -f if 60 The handle 3 has'a chamber lorjthe magaziner carrying the cartridges Gand having the follower 7 and iollower"spring18 all 'of common' construction* l The `structurealso'includes the following-"65 parts fri hammer 9,v hammer spring 10,' hammer spring Ytliimble` `11, sear 12, Sear pivot pin and arm 13, sear bar 14,.sear -bar` disconnector 15, trigger 16, front. sight-,'17 vfrear sight 18, extractor't?z and "ejector 48.' These 70 parts are all infcommon use in gun construc' ti"on=Y and perform their usual functions.l

:One of thev improvementsfof the construc-- tion herein-shown consistsy in thel method oflockingthe bolt`19-to the receiver 2' at' "75 therltinielof'firing. yThis is doneby the' bolt lock whichconsistso'f a pin 2O'mountedv to slide in` a poeketil)EL on ftheV undersideof the boltv and'transverse toits axis. This bolt lock lis urged downward` by a spring 21 80 which acts against a bolt lock pin22 in the bolt lock, both said lock and pin beingV slottedlfor 4the ringlpin-23- A retaining pinf24; holds fthe' boltlock i-n place'while asf sembling. The construction-of the bolt'jlock 85 so fardescribed, is very similar toV that shown in the application already referred to, 'the "only difference, but that;l a very `importantone,-be'ing thatv the contacting sur` faces 25 between'the'bolt lookl and the 're-r 90 c'eive'r arev cut at aslight angle. "In the draw! ings this angle isv almost'imperceptible,` it being only'about six and one-half degrees;y It has been determined in mechanics that, between metallic surfaces,fan angleof live degrees will'not slip under constant pressure. "Thef'proper angle vhere .is approxi-` mately somewhere between sixand seven `degrees. By putting a rod', in the barrel against the bolt and applyinga :weight it will befonnd lthat the bolt, when 'they bolt lock is' in place,will sustain an almostfunlimited weightf; in 'fact the parts would; be crushed Vbefore the',I bolt ,lock would slipj-out.

A" quick vblow or shock', however, will re-,105A

,I have produced whack-operated automatici gun. Moreover., as the t bolt lock Slips, out,

l the shockseems to bev absorbed and Yits, full force, is not. A@felt by the person firing the son; The@ iSbo*ilerclckf'elttben 'Whcliiftbe barrel and receiver 'are' permitted tuo-'recoil 'on the handle and very materially less,` in

both cases, than when a straight bolt lol is used which does notl permit the bolt to be released. The determiningjactors arejhe, angle 'of the surfaces 25 and the `length Vof and; the tension ov-the'bolt. return-spring 26j-the Weight of-the bolt also affecting 1 itl slightly. Thetangle of. the contact surfaces and-thedistance the bolt lock has tofmove,

1 are the'chief things to be consideredoinad.

justing .the gun 'to 'functionfproperlyi forja '.The boltyreturntspring 26is mounted Va hole 27 Vwhich is cut-partly in theboltenel-partly in the receiver andgs helolfon-a` gudevvrod .2S-:The fronteildy of--this rod just, barely enters a blind hole 29 fin a, boss 3Qy '25 v have, a free fit in .a correspondingly shaped the linchpn iS clear ilo'.k By pushing they formed ori-the front-end ofthebolt. Therear end of ythe rod has ,flattenedsdes ,3l ywhich opening in an earf32ofa ,sleeve owhchis mounted C011,@@Iltricwith,V the bolt and, Whichy alsoaflordsa guideforthe firing-pin'. The

2,8 ic.lprovflol with alot-op or lug .3.4; I f on its bottom Side Ajujstnside the; eanvSZrand-f, tiohas, a semiecircularzct35011 tsuppex; side'. lnchpin 36, horloge `Senofoirculan cut. 37,5 'extends crosswise` of: the receiver..;

This out' is in line with the guide rod When vided?. with lugs 40 which Straddle the stopy lug 3ft when .the parts aref'inthe Position' shown im Figure 1.A TherlnelopinV extends through a cut across said heed and keeps :theI

sleeve 38`romturning on the-'rodl 2:8.` The bolt. return Spring 26 acts. bctweentbe'boss.

`V 30, of thel bolt and the head fof-the. sleevev Thel head 39 rests againStfthelinchpin,` taking the thrust of the*boltjreturnl Springe-1t will be seen that Wlbelufthel boltlpok is raised tand thel bolt vis thrown back v to the rearlby the explosive charge, sog-that,

the bolt stop 19" reaches! the rear- Wallof the; opening 2% on the right hand sideV of theu receiver (l5"ig1o1re4.),y that the bolt return springwill, be put under-tensiom/and asgthe;

,l "infthe receiver is left lentirely unobstructed for the, ejection of the empty shells. o T begbclt Spring, ccd, totbleorlcc takcncot;

Withoutgremovingthe sleeve 33 :when the boltis out yof the"receiver;*byl pushingV for- Ward rthe rod 28until it is disengaged from vtbe cer 32o-the fit, ofthe rod 2,8 the. blind hole 21S/'being loosey enou l; to permit a slight Sidewise movement. o 'the rear'end of thev rod;y

loadthe first shell or to eject a loaded shell, tho/bolt look20km gto be raised. Thisis effected by an idle pin 42 in the handle, which is acted on bytherear end of a levert,

k43,Y they `lever being mounted inl a suitable l i recess-amado ,for it in the left side .oi the,V

handle vand heldin pliwobr a pin 454. By,

pushing down. Aon ai choc dor' knurleo.

In order to Withdraw the bolt by hand thumb .piece l5-xm 'thefrontendoftheleverz` i 43 vthe bolt `lock will be raised, `when, thev this lpwlpoteo 1,111 al1-automatic cfrcr-m the' 'Ogmbinaf tionlof a bolt with areeeiver and abolt refV turnspring mounted in a longitudinaLopenf ing cutape'rtelly rfxqsold bolt and partiallyatf the ends of f. the; bolt, around which. Said.

"bolt'may :be vdrawn backby groomingy ther knurled bolt lugs: 46 which areprovifledioc -msed receiver@ 'rod ymountedotitis `ends Spring iS ctileol;y a Sleeve sl-idablo Seid i' i rod and-Serving 'as ,the fixed end boerin for said spring,v andA en abutmentfior Sai .Y

sleeve .mountedin lSaid receiver.; Y Y. 2,111 en `2h11`to11f1eti-c 'reerm o the cobbimef tion ofc, a receiver with .a bolt aboltretum 'Seeing .c guide-rod for -Scdspcins mounted. 'flbolt e-Slecveslidoblc I1saldk :guide in sai o n i rod and adapted; f .totake the enwthrust oi-A 'said s},),ring,andfa linchpin mounted in the side walls of said, .receiver and adapted( act as an abutment forlsaid S190Ye,sa id Y *linchPn-ond scid guide` rod beinercvcrselyi out away. and Seid@ guide rod, Serving* es.; c.

lockforf-sudflinchpla; f o o o 3. In an vautonrlatio firearm the-combinaf@ tion oofc'rcccivcrwth c bolt., cbclt return Sicribe,4 a; guide rod ltot Seid.; SPriosmcun/ted f in; Said bolt: tbcnronlt end otscidf. guide-rod; beino heldin a blind hole ina boss formed; on mi@belemmeren.end of vsaid .geraamd herring-.flattenedSidcsaod.cotrcdfiomopcnf ing of similar shape'in an ear at the reafrfendv a of saidbolt, said guide rod.-l1aving a stai lug adjacent to saidI earE and havingI a; noto on the, sideJ opposite said lug, a, sleevelidable on said rod and adapted to i. take :the end;

tbrustcf Said Spring-cs the bolt is opened, f

Seid; Slee-Vehcveg .ahead with two omnes which inclose the lugv-.of-said guide r0d a, linchprin -Inounted yin .theV side Walls.; Of said reccirel: and-Servingacfen abut-ment for: scid..

withI .the notch of; said, guide rodE 4when sai'lg guidel rod is ,pushedjslightlyforward: but

beleg out ctrcgistc Writhscldfnctchwhea said guide rod is in its normal rear position, whereby the guide rod looks the linchpin and the linchpln permits the free movement of the guide rod.v

4. In an automatic irearm the combination of a receiver With a bolt, a bolt return spring, a guide for said spring mounted in said bolt and a transverse linchpin mounted in the side Walls of said receiver, said guide rod being adapted to look said linohpin and 10 sadlnohpin being adapted to serve as an abutment to take the thrust of said sprin when the bolt is opened.

' GRANT HAMMOND. 

